Manual telephone system



March 18, 1930. J. H. LEVIS, JR

' MANUAL TELEPHONE SYSTEM Filed April 23, 1928 INVENTOR Jenn H. Laws 0R. BY A9 'ATTORN Y od o \rmwr wziobzai 1 mhOEuwao Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE JOHN H. LEVIS, JR., OF ROCHESTER, NEW YORK, ASSIGNOR TO THE STROMBERG-CARL- SON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEW YORK, A. COR- IBORATION OF NEW YORK MANUAL TELEPHONE SYSTEM The toll positions of a manual telephone system are frequently provided with a plurality of combination cord circuits by which a toll line may be connected either with another toll line a rural telephone line or a common battery telephone line. Frequently the rural telephone lines are not properly maintained and portions of the toll lines are sometimes functioning below the desired efliciency so that in order to provide suitable transmission from a toll line to such a rural line or another toll line it is necessary to in clude a repeating coil in the combination cord circuit used to interconnect these lines. As is well-known, each cord circuit has associated therewith a plate or key strip on which there are mounted several keys by whichthe following. operations may be'controlled such as ringing either the answering or the calling end of the cord circuit, permltting the operator to converse-either with the answering or the calling end of the ,cord c1rcu1t, bridging the operators telephone set to the cord circuit or to permit a monitoring connection to be established to the cord circuit. Such a key strip occupies all of the space that can be convenientl 1 used crosswise of the key shelf and in thepast, manufacturers of such toll positions of a switchboard have been confronted either with the difficulty of crowding the key shelf or else utilizing one of the present keys ofthe strip for the pur pose of cutting-in a repeating coil w1th the I consequent omissionof the necessary func- 35 tion controlled by, the replaced key. This difiiculty arose from the fact that 1t was necessary to utilize a repeating coil cut-1n key for each cord circuit. p p

In accordance with the present invention t is proposed to utilize a common repeating coil cut-in key for a plurality of cord circuits of a toll position and to rearrange each of the cord circuits so that they may be control-ed by thecommon cut-in key and still prevent the functioning ofone cord circuit from interfering with that of the other cord circuits. 7 I i Other features of the invention include the j novel arrangement for indicating when a re..- peating coil is included in a cord c1rcu1t and 1928. Serial No. 272,111.

also means including a common switch whereby the repeating coil may be cut out of any cord circuit at the will of the operator.

For a clearer understanding of the invention reference is made to the drawings wherein Fig. 1 represents a portion of a telephone system in which there is indicated at' the extreme left a toll line and atthe extreme right there is indicated a commonbattery telephone line and anothertoll line. In the center of this figure there is represented a combination cord circuit in which the present invention is included. Fig. 2 represents a 7 key strip mounted on the key shelf of the toll operators position in the switchboard, a key strip of this type being provided for each combination cord circuit. 1 x o It is believed that the inventionwill best be understood by describingthe operationof establishing various connections such as Y a toll connection through the cord circuit shown in Figure 1. When a connection has been established at a distant exehangetnot shown) to the toll line or trunk 5, the trunk relay 6 is operated'in the well-known manner to complete a circuit for lighting the" I trunk lamp l lighting of this lamp inserts the plug P of; one of the combination cord circuits at her position into the ack J of'tlie'toll line. On

completing this portion of the iconnection The operator upon noting the the sleeve relay 8 is operated from grounded battery, winding of this relay through; the

sleeve contacts of plug P and jack J winding of the cut-off relay 9, to-ground. The sleeve relay 8 and the cut-offrelay 9 are both operated, the last-named relay serving to disconnec't-the' trunk relay 6 from the trunk line 5 and to extinguish the trunk lamp 7.' The operator then closes the bridging :liste ning key Etc connect her telephone setlto the trunk line 5 so that she may inquire the num-' ber designation "of the wanted line. 'The connection from the operators telephone set through the key E to the trunk line 5 extends through conductors 1O and 11 and through the normally closed contacts of the keys A and D e Let it be'assum'ed that the wantedconnection is to another toll line such as '12. 5 The through the winding of the sleeve relay 28, sleeve contacts of the jack and of plug P, winding of relay 14, and winding of relay 15 to grounded battery, the relays 14,128 and marginal 15 are all operated. The operation of relay 14; closes abreak-point in the tip conductor of the calling cord and the operation of the relay 28 disconnects the line relay 29 from the control of the substation generally designated 30. The relay 1-5 when operated at its left hand contacts and armatures connects the battery-feeding relay 41 to the calling end of the cord circuit and the closure of the innerarmature and front contact of relay15 completes a circuit through the wind-v ingof relay 18 and the resistance to grounded battery which is efiective to operate the relay 18 for the purpose of connecting the repeating coil windings in series with the calling and answering ends of the cord circuit. -The called substation 30 may be signalled by depressing the ringing key B in the well-known manner.

At the termination of this call the subscriber replaces his receiver on its switchhook which is eiiective to open the line circuit which in turn causes the deenergization of the battery-feeding relay 31 whose windings have been connected in series with the called line. The deenergization of the relay 41 is efi ective to light the calling supervisory relay 32 in a circuit from grounded battery throughthe lamp, back contact and armature of relay 4C1, inner front contact and arinature of rela 1 15, to round. When the ori inating operator at the distant ofiice desires to signal for disconnection the relays 50 and 51 are operated in the manner previously de scribed to light the disconnect lamp 53 associated with the answering end of the cord circuit. The operator at the position including the cord circuit of Fig. 1 on noting the lighting of the lamps 32 and 58, removes the plugsP and P from the jacks with which they have been in engagement causing the cord circuit to revert tonormal condition.

What I claim, is: I r v 1. In atelephone' system, an incoming line,

a plurality of outgoing lines, a plurality oi cord circuits for interconnecting said incoming line with any of said outgoing lines, each of said cord circuits'normally having its ends conductively connected together, and means including a manually controlled device for V conductively separating but inductively connect ng the endsof any desired one of said cord circuits, 7 a

2. In a telephone system, a plurality of incoming lines, (t-plurality of outgoing lines, a plurality of cord circuits for interconnecting said incoming lines with any ofsaid outgoing lines, said cord circuits normally having their ends conductively connected together, means responsive to the connection of said cord circuits to certain of said lines for automatically rendering said cord circuitsinductively continuous but conductively discontinuous, and means including a device common to said cord circuits made effective by theconnection of any cord circuit to any of the remaining telephone lines for rendering said cordv circuit inductively continuous andconductively discontinuous at will.. v

3. In a'telephone system, incoming lines, groups of outgoing lines, a plurality of cord circuits for interconnecting said incoming lines with. any of said outgoing lines, each cord circuit being provided with a repeating coil normally electrically disconnected therefrom, means responsive to the connection of said cord circuit with any one of a certain group of said lines for-connecting said-repeating coil in said cord circuitwhereby its ends are inductively connected together but conductively separated, and means including a switch common to a plurality of cord 1 circuits for connecting the repeating coil into its associated cord circuit in response to the connection of said cord circuit to the other group of outgoing lines. 3

4. In a telephone system,'incoming lines, a plurality of outgoing lines, aplurality of cord circuits for interconnecting said incoming lines with any of said outgoing lines, each cord circuit being provided with a repeating coil normally'electrically disconnected there-r from, means responsive tothe connection of said cord circuit with any one of a group of saidlines' for connecting said repeating coil in said cord circuitwhereby its ends are incircuits for interconnecting said "incoming lines with any of saidoutgoing lines,- each cord circuit being provided with a repeating coil normally disconnected from its associated cord circuit, means responsive to the connection of said cord circuit with any line of one group of said lines for'connectingsaid repeating coil into its cord" circuit whereby its ends are inductively connected together but conductively separated, means including a switch common to a plurality oiicord circuits fOI connecting the repeating coil into its as sociated cord circuits in response to the connection of said cord circuit to. any line of the other group of outgoing lines, and means common to said cord circuits for disconnectlng cord circuit.

any repeating coil "from its-"associated 5 :5 Inza; telephone-l's ysterngia plurality of iiicomingilines',ftwoz groups of outgoing lines,1 the lines of onexgroup being'electrically dis- "tinguished in one manner'and the lines ofthe' other group heing I electricallydistinguished in a different-manner, apluralityof cord- O11- cuits {for interconnecting lsa'id incoming "lines with the-outgoing lines] of either of said groups, each-cord circuit beingprovided with i m; a repeatingcoil norinally disconnected theree v from;:auto1natic means responsiveto thelc'om' nection-of any cord, circuit t'ozone' of said group's: ioraautolnatically connecting the re- I peatingcoil operativelyin:its*assoc1atedcord;

: trolled. deviceefiectlveonrthe -connect1onof any-cord circuittoany'of the second groupof I I 771i Infa telephone system; aeplurality of incircuit, andnie'ans includin'g a-vmanually con lines for'electri'cally connecting the-repeating: coilintofltsassoclated circu t:

Coming lines,;t w.o. groups of outgoing lines, thelines of one group belng electrically d1s L tinguishedi in one manner and the outgoing lines ofi/the other group being; electrically distiguish'ed in a 'difierent *manneryaplurality of; cord circuits for interconnecting said incominglinesi with the outgoing lines" of either of saidigroups, each cord c1rcu1t-- beingiiprovided with a. repeating coil nor '80] mally' disconnected] therefrom, automatic means responsiveigto,the connection of any-- cord' clrcuit to= oneof sa 'd" groups for auto-e vInatica-lly connecting the repeatingcoil op- 3 e'ratively in 'its associa'ted cord circuit, means includinga manually" controlled device; ef

fectilve: on e the connection of any cord circuit g toanyaof-thesecondgroup'of lines'forelecl trically connectingtheirepeating coilfi-ntoits associated circuit; and; a second device com inon toQsaid cord circuitsoperated-at'fwill'for discol'inecting any repeating coil froiniits'associated circuit. Whenit is connected to any lineof th'esecondgroup.

- 7 8. In-ia 'telephone system,'a; plurality of coming lines, two groups of outgoing lines, a

.7 g plurality of; cord circuits for interconnecting? Y sald lncomlnglines wltlif'any :ofsaldout-f 1 going 111165, each cord CIICUIt'bell'lg' plfovlded with a repeating coil- Tnornially electrically disconnected froni itsias'sociat'edcord circuit, monitorlng"mechan sm" common-to said'cord circuits; a monitorlng key for' connectlngsaidamonitoringfn echanism, t0 itscordf circuit-1 "in ea'ns. responsive to the connection:ofganyE cord; circuit toany outgoing l-line -in "one of goingf lineiof the i second group, saidz othe r meansbeingcontrolled'in'part by'saidmoni5 to any outgoing line oi" the s'ccon'dggroup eludingthe nionitoringikey ofsaild cord;cir e i, c cult for;render ng saidlain p efiective, and" dlsconnect ng means lncludlng a c'ut-outg I '9; Ina telephone-systemg a plurality; of-in' coming lines, two groups of outgoing lines;

a plurality of cord circuits for interconnecting said incorning lines With-any, of said outgoingilines, eachfcord vcircuit being provided with a; repeating coil normally electrically e disconnected: from its associated cord circuit, mon toring means-common to sa1d cord clr-f cuits, a monitoring key individual to each. 1 cordi circuit for connecting said monltorlngmeans to its cord circuit, means-responsive to theconnection of anycordfc rcultto any outgoing line in one of said-groups for-auto matically'electrically connecting 'said 'repeat:

ing'coil in circuit with its associated cord'circuit other means including a device common 7 to-said'cord circuitslfor electrically-connectf' ing the repeating-coil in its associatedcord circuiton the connection of said cord'circuit said othe'r'means being controlled inp'artj by said n1on1tor1ng key,"a lamp common tosald cordcircuits'for indicating when said cord circuit has-it's asso'ciatedlrepeating coil elec- 90 trically included therein, and meansincluding the monitoring keyof said cord circuit;

for 'ren dering the lamp of its'fcord circuit ef-f fective. v f V V "10. In a t'elephonesystem, a plurality of incoming lines, two' groups of outgoinglines,

a plurality of cord circuits for'interconnectA j ing said incoming lines with any of said outgoinglines each cord circuit being pro'vided" with a repeating coil normallyelectrically disconnecte'd'from its associated cordcircuit, monitoringineans common to saldflcord cnrc uits; a monitoring key individual to' each' cord CII'Clllt for connecting said mon tor ng;

means to its cord circuit, means responsive to the connection of any cord circuititoany outgoing line one of said groups for auto; rhatically electrically connecting said 'repeating coil incircuit with itsassociatedcord f circuit, other means-including: a device corn-' circuit to .any outgoing line of the second mon to said 3co rd circuitsfor electrically con nectlng the-repeating coil its' associatedi' I V cord clrcult-onthe connection of-saidcord 'g'roupl'jsaid other means beingcontrolled: in

electrically included there-in' and means in switch 1 common '4 to all "of said ico iid circuits 1 andcontrolled in part by-t monitoring-key 1 of any: desired "cord circuit "for electrically disconnecting the repeatingcoil Lfrorn saidi desiredcord circult. 1

""In Witness wvhereof,Thereunto suhscribe" mynam th s 0-d y ema %=';DP

, a JOHN f i1 part by saidinonitoring keyya lamp cornnion l5 v I 0 said cordclrcuits for,-flid catlng when said cord circuit has its 'associated repeating coil 

